Snow melting apparatus



Dec. 14, 1965 WATKINS 3,223,080

SNOW MELTING APPARATUS Filed Aug. 5, 1962 I INVENTOR JLMAQ. 4 yam;

A TTORNE Y5.

United States Patent Ofifice 3,223,080 Patented Dec. 14, 1965 3,223,080 SNOW MELTIN G APPARATUS Franklin M. Watkins, Flossmoor, Ill., assignor to Sinclair Research, Inc., Wilmington, Del., a corporation of Delaware Filed Aug. 3, 1962, Ser. No. 214,729 1 Claim. (Cl. 126343.5)

This invention relates to a snow-melting device. It relates more particularly to relatively small portable snow melting equipment that may advantageously be used by home owners and service station personnel. The device on a larger scale employing the same principles of operation may also advantageously be applied to the elimination of snow by for instance, municipalities, airport operators, parking lot attendants, etc.

Heretofore the snow melting equipment available has been confined to a large extent to cumbersome and expensive machinery which may be stationary or adapted for use on truck, tractor or locomotive equipment. These machines are ordinarily provided with high pressure fuel systems i.e. systems which use high oil pressures usually in excess of 100 pounds per square inch which causes fuel to be fed at a high rate usually in excess of 5 gallons per hour and employ a variety of heat transfer surfaces to effect the melting of the snow. Other known melting devices in service feature submerged combustion units wherein hot gases from high pressure burners are exhausted below the surface of a pool of water into which snow is dumped to effect melting. Submerged combustion units known today are large and costly though they attain 95% heat recovery. Still other snow melting devices flow deflecting streams of combustion products directly against the snow from units traveling over the snow surface. Snow melting machines are also known that effect a substantial portion of the melting process by indirect heat exchange through heat conducting surfaces in communication with a source of heat. All known methods have insurmountable weaknesses, most common of which are high initial cost, lack of portability or low efficiency in transferring heat to snow. The instant invention utilizes the readily available, low cost, low pressure household type burners that is, burners whose full consumption is from about one-half gallon to about two gallons per hour and where oil pressures employed range from about forty pounds to about seventy pounds per square inch with the air being at substantially atmospheric pressure. The instant invention, using burners of this low capacity, which burners incidentally represent a high proportion of the oil burners that are sold and used, attains unpredicted high thermal efficiency by direct contact between hot combustion products and the continuously cleaned surfaces provided by melting snow.

It has been found in my apparatus that hot combustion gases contacting the snow create freshly melted surfaces which promote efiicient heat transfer as evidenced by the low temperature of exhaust gases passing through the snow and out an open portion of the device. The temperature of these exhaust gases generally has been found to be cool thus indicating the removal of nearly all available heat in the melting process. In brief the device of my invention comprises a burner, combustion chamber and gas distributing means with snow being placed on the latter two members.

Most often the device has a receptacle for receiving the gas distribution means and sometimes the combustion chamber. The receptacle used in the instant device may be of any suitable shape such as for instance a cylindrical container, a box member, a tunnel, a trough, etc. Preferably, to increase the thermal efficiency and confine heat transfer to snow within a cylindrical container or a box, the receptacle may be insulated with for instance asbestos, mill board, cork, fibrofelt, mineral wool, rock cork, etc.

The combustion chamber must be insulated to prevent unburned fuel impinging on a cold surface and being reduced in temperature to a point where it forms soot and is not completely consumed. Incomplete burning leads to soot and dirty, inefficient operations. Preferably the inner surface of the chamber is insulated with a heat resistant material such as a refractory and may even glow during operation to enhance combustion. Suitable refractories are, for instance, Alundum, bauxite brick, chrome brick, fire clay brick, magnesite brick, silica brick, silicon carbide, zirconia brick, etc. Usually the melt and perhaps a portion of the snow assume a position beneath the gas distributing means to be described below and often beneath the combustion chamber to insure more efficient heat transfer. The snow may even be packed around the sides of the combustion chamber and gas distributing means.

The combustion chamber should be of such form that direct contact of the snow charge with the combustion operation or flame is substantially avoided, and thus the chamber has a solid top plate to protect the burning area from falling snow and melt. The combustion chamber provided may in this invention be a member with a solid top and side walls with a substantially open bottom to permit the products of combustion to pass upwardly around the sides and directly into the charge of snow introduced into the receptacle. This type of chamber may alternatively be provided with a bottom member supplied with a plurality of apertures, i.e. perforations or slots, to permit passage or communication of combustion products upwardly into the snow charge or the chamber may be a closed-bottom member. In all of these embodiments the combustion chamber is associated with gas distributing means to effect more intimate contact of combustion products with the snow charge.

The gas distributing means facilitates the diffusion or dispersion of the gas more effectively into the snow charge by having a solid top, an open bottom and solid or open sides. The incorporation of gas distributing means into the device of this invention also aids in the minimization of heat losses by providing more effective contact of the gas with the snow. The gas distributing member may take any suitable shape as for instance, bafiles, deflectors, open-bottom tunnels which may be inverted V-shaped or semicircular or rectangular in cross-section and is preferably essentially completely surrounded by the receptacle for holding the snow or the melt in heat transfer relationship to give an efficient operation, although efiicient operation may also be realized when this preferable arrangement is limited to, for instance, above and below the distributing means.

Further objects, features and advantages of this invention will be apparent from the following description of a typical illustration of an embodiment of this invention in connection with the accompanying drawing wherein:

FIGURE 1 is a side elevational view of this invention with parts broken away; with FIGURE 2 being a front end elevational view thereof; and

FIGURE 3 being a top plan view of the device of FIG- URES 1 and 2 also with parts broken away.

Referring now to FIGURES 1, 2 and 3 showing the instant invention, the snow melting device comprises a combustion chamber 102 provided with a layer 104 of insulating material and a burner 106 at one end. Fixedly attached to the end opposite burner 106 is an elongated trough member 110 comprising bottom member 1'12 and side members 114 and 116. Vertically disposed and in engagement with bottom member 112 are a plurality of dams 118 fixedly attached at their ends to trough side members 1'14 and 116. The longitudinal axis of said dam members is coplanarly perpendicular to the longitudinal axis of said bottom member 112. These dam members extend vertically from the bottom member 112 at a distance sufiicient to provide a shallow water pool on the trough bottom. Disposed within said trough member 110 is elongated tunnel member 120 comprising solid semicylindrical portion 122 and discontinuous flange members 124. The solid crown of semi-cylindrical portion 122 is disposed below the level of side members 114 and 116. Flange members 124 are fixedly attached intermediate side members 114 and 116. This embodiment may also advantageously be adapted to be used in clearing large surface areas of snow by providing a combustion chamber in association with the gas distributing means below ground level in, for instance, concrete channels provided with a grate flush with the ground level. Any suitable drainage system may be employed to carry off the efiluent.

A low pressure fuel oil burner 106 was fired into combustion chamber 102 with exhaust gases issuing into open bottom semicylindrical heat tunnel 120. Dams 118 provide a shallow pool for melted snow and overflow is discharged from the device out the trough end remote from the combustion chamber 102, The combustion chamber and trough member may advantageously be surrounded by the snow charge and/ or melt which is formed by melting. The presence of the snow and/or melt not only acts as an insulating layer for these members so as to permit a substantial reduction of heat losses to the atmosphere but it also serves to promote a more efficient heat transfer medium by which effective utilization of the heat content of the combustion products is achieved. The device to attain greater portability characteristics may be provided with wheels at one end of the apparatus.

While this invention has been described in connection with a typical preferred embodiment, it is to be understood that this has been for purposes of illustration and that the practice and the embodiment of this invention sides permit the passage of combustion gases laterally and upwardly along the length of the tunnel member to contact directly snow placed above the said distributing means, said tunnel member being positioned to receive snow directly thereon and being underlain by a receptacle comprising a trough-like member provided with a plurality of vertically disposed dam members engaging the bottom of said receptacle and providing a shallow water pool on the bottom of the receptacle.

References Cited by the Examiner UNITED STATES PATENTS 557,163 3/1896 Springfels 126-343.5 595,072 12/1897 Smith 126343.5 982,531 1/1911 Ringbom 126-3435 1,098,950 6/1914 McGuire 126343.5 X 1,125,732 1/1915 Savonius 126343.5 1,204,400 11/ 1916 Br-auninger 126-3435 1,572,414 2/1926 'Wilbert 126343.5 X 1,665,503 4/1928 :McClave et a1 126343.5 3,011,493 12/1961 Zieba '126-343.5 3,052,231 9/1962 West et a1. l26-343.5 3,098,478 7/1963 Philbrook l26-343.5

JAMES W. WESTHAVER, Primary Examiner.

PERCY L. PATRICK, Examiner. 

